Installation of cured in place liners with air and steam and installation apparatus

ABSTRACT

A process for lining an existing pipeline or conduit with a flexible resin impregnated cured in place liner by pulling in the liner and inflating an eversion bladder with air and curing the liner with flow-through steam without loss of pressure is provided. The liner includes a resin absorbent material in tubular form with an impermeable membrane forming an outer layer. The absorbent material is saturated with a thermoset resin and pulled into the existing conduit. A flexible inflation bladder is passed through a gland mounted on an eversion apparatus and everted into the collapsed liner. The gland is pressurized to isolate the eversion bladder. As the bladder reaches the distal manhole, it enters a receiving canister where it is punctured while maintaining air pressure within the bladder. Steam is then introduced into the bladder to cure the resin and is exhausted through the receiving canister. The bladder is then removed and lateral service reinstated.

BACKGROUND OF THE INVENTION

This invention relates to a method for installation of a cured in placeliner into an existing conduit by pulling in and inflating the liner andmore particularly to a method of trenchless rehabilitation of anexisting conduit by pulling into the existing conduit a resinimpregnated liner, everting an inflation bladder into the liner with airand curing the resin with continuous flow-through steam without loss ofpressure in the bladder and to the apparatuses for practicing themethod.

It is generally well known that conduits or pipelines, particularlyunderground pipes, such as sanitary sewer pipes, storm sewer pipes,water lines and gas lines that are employed for conducting fluidsfrequently require repair due to fluid leakage. The leakage may beinward from the environment into the interior or conducting portion ofthe pipelines. Alternatively, the leakage may be outward from theconducting portion of the pipeline into the surrounding environment. Ineither case, it is desirable to avoid this leakage.

The leakage may be due to improper installation of the original pipe, ordeterioration of the pipe itself due to normal aging or to the effectsof conveying corrosive or abrasive material. Cracks at or near pipejoints may be due to environmental conditions such as earthquakes or themovement of large vehicles on the overhead surface or similar natural orman made vibrations, or other such causes. Regardless of the cause, suchleakages are undesirable and may result in waste of the fluid beingconveyed within the pipeline, or result in damage to the surroundingenvironment and possible creation of a dangerous public health hazard.If the leakage continues it can lead to structural failure of theexisting conduit due to loss of soil and side support of the conduit.

Because of ever increasing labor and machinery costs, it is increasinglymore difficult and less economical to repair underground pipes orportions that may be leaking by digging up and replacing the pipes. As aresult, various methods had been devised for the in place repair orrehabilitation of existing pipelines. These new methods avoid theexpense and hazard associated with digging up and replacing the pipes orpipe sections, as well as the significant inconvenience to the public.One of the most successful pipeline repair or trenchless rehabilitationprocesses that is currently in wide use is called the Insituform®Process. This Process is described in U.S. Pat. Nos. 4,009,063,4,064,211 and 4,135,958, the contents of all of which are incorporatedherein by reference.

In the standard practice of the Insituform Process an elongated flexibletubular liner of a felt fabric, foam or similar resin impregnablematerial with an outer impermeable coating that has been impregnatedwith a thermosetting curable resin is installed within the existingpipeline. Generally, the liner is installed utilizing an eversionprocess, as described in the later two identified Insituform patents. Inthe eversion process, radial pressure applied to the interior of aneverted liner presses it against and into engagement with the innersurface of the pipeline. However, the Insituform Process is alsopracticed by pulling a resin impregnated liner into the conduit by arope or cable and using a separate fluid impermeable inflation bladderor tube that is everted within the liner to cause the liner to cureagainst the inner wall of the existing pipeline. Such resin impregnatedliners are generally referred to as “cured-in-place-pipes” or “CIPPliners” and the installation is referred to a CIPP installation.

The CIPP flexible tubular liners have an outer smooth layer ofrelatively flexible, substantially impermeable polymer coating theoutside of the liner in its initial state. When everted, thisimpermeable layer ends up on the inside of the liner after the liner iseverted during installation. As the flexible liner is installed in placewithin the pipeline, the pipeline is pressurized from within, preferablyutilizing an eversion fluid, such as water or air to force the linerradially outwardly to engage and conform to the interior surface of theexisting pipeline. Cure is initiated by introduction of hot water intothe everted liner through a recirculation hose attached to the end ofthe everting liner. The resin impregnated into the impregnable materialis then cured to form a hard, tight fitting rigid pipe lining within theexisting pipeline. The new liner effectively seals any cracks andrepairs any pipe section or pipe joint deterioration in order to preventfurther leakage either into or out of the existing pipeline. The curedresin also serves to strengthen the existing pipeline wall so as toprovide added structural support for the surrounding environment.

When tubular cured in place liners are installed by the pull in andinflate method, the liner is impregnated with resin in the same manneras the eversion process and positioned within the existing pipeline in acollapsed state. A downtube, inflation pipe or conduit having an elbowat the lower end typically is positioned within an existing manhole oraccess point and an everting bladder is passed through the downtube,opened up and cuffed back over the mouth of the horizontal portion ofthe elbow. The collapsed liner within the existing conduit is thenpositioned over and secured to the cuffed back end of the inflationbladder. An everting fluid, such as water, is then fed into the downtubeand the water pressure causes the inflation bladder to push out of thehorizontal portion of the elbow and cause the collapsed liner to expandagainst the interior surface of the existing conduit. The eversion ofthe inflation bladder continues until the bladder reaches and extendsinto the down stream manhole or second access point. At this time theliner pressed against the interior surface of the existing conduit isallow to cure. Cure is initiated by introduction of hot water into theinflation bladder which is circulated to cause the resin in theimpregnated liner to cure.

After the resin in the liner cures, the inflation bladder may be removedor left in place in the cured liner. If the inflation bladder is to beleft in place, the bladder will generally be one that has a relativelythin resin impregnable layer on the inside of the impermeable outerlayer. In this case, the impregnable layer after eversion will cause thebladder to adhere to the resin impregnated layer of the liner as is wellknown in the art. At this time, entry into the manhole or access pointis required to open the liner to release the water used to inflate thebladder and to cut off the ends extending into the manholes. When theinflation bladder is to be removed, it may be removed by pulling at theevasion end on a holdback rope attached to the trailing end of theinflation bladder used to control the speed of the eversion. This isgenerally done after puncturing the bladder at the receiving end torelease the water used to evert the bladder and initiate the resin cure.Finally, the downtube can then be removed and service can be reconnectedthrough the lined pipeline. If intersecting service connections arepresent, they would be reopened prior to resumption of service throughthe lined pipeline.

When a cured in place liner is installed using the pull in and inflatemethod, the outer impermeable layer of the liner remains pressed againstthe interior surface of the existing conduit. Certain advantages may beattained by this method of installation because the resin in the resinimpregnable layer of the liner is trapped between two impermeablelayers, namely the outer coating of the liner and the inflation bladderon the inside. Accordingly, there is little or no resin migration out ofthe liner. In a pull in and inflate installation, the liner coating neednot be as strong as required in an installation by eversion, because thecoating is not subjected to the pressure head required to evert theliner using the eversion process. Additionally, the coating does notcome into contact with hot fluid circulating during the resin curecycle. Thus, the liner may be of more uniform thickness in a pull in andinflate using an inflation bladder cured in place process compared towhen the liner itself is everted.

While the pull in and inflate method has these advantages, theinstallation process is somewhat more complex than an eversion. Pull inand inflate requires banding the inflation bladder to the downtube elbowand securing the collapsed liner already positioned in the existingpipeline to the downtube. This requires work within a restricted manholespace. Additionally, at the end of the installation, the inflationbladder may need to be removed after being cut at the distal end torelease the water used as the inflation fluid.

While the pull in and inflate method utilizing water does have thevarious advantages noted above, the shortcomings tend to increase laborcosts which are a significant aspect of the installation process.Accordingly, it is desirable to provide a rehabilitation method usingpull in and inflate, wherein the liner is inflated with air and theresin is cured by steam flow-through, to take advantage of the energyavailable in the steam to provide an installation method which is fasterand more efficient economically than various rehabilitation methodscurrently practiced.

SUMMARY OF THE INVENTION

Generally speaking, in accordance with the invention, a method ofrehabilitation of an existing pipeline by pull in and inflateinstallation of cured in place liners using air to inflate an inflationbladder and curing with flow-through steam without loss of pressure inthe liner is provided. A resin impregnated liner is pulled into theexisting pipeline to be repaired and cut at the ends to extend into bothmanholes. An inflation bladder in a length somewhat longer than thepipeline to be lined is attached to an inflation elbow that is placed inthe upstream or eversion manhole and the collapsed liner is secured tothe outlet end of the bladder on the elbow. The elbow includes a glandat the inlet side through which the bladder passes and which can bepressurized to seal against the bladder during inflation. The bladder iseverted using air causing the liner to expand progressively. When thebladder approaches the downstream access point, the bladder isrestrained and clamped at the gland on the inlet side of the eversionelbow. The bladder is then allowed to evert further into a receivingcanister in the downstream or receiving manhole and punctured. Airpressure is maintained in the bladder and exits the canister through anexhaust line attached to the distal end of the canister.

While maintaining pressure in the bladder, steam is introduced into theelbow downstream of the gland and passes into the bladder to initiatethe cure and exit through the canister exhaust. After the resin in theliner is cured, the steam is turned off and the air pressure is adjustedto maintain pressure in the bladder and maximize cooling. The inflationbladder is then withdrawn by de-everting using a power spool at theeversion end. Any condensate in the bladder is removed through acondensate trap in the elbow in the eversion manhole.

In a preferred embodiment of the invention, an easement vehicle carriesa spooled inflation bladder of appropriate length on a staging spool tothe upstream access and includes valves and regulators for applyingpressurized air for eversion of the bladder and steam for curing of theliner and removal of the bladder after cure. In a most preferred aspectof the invention, the inflation fluid is air which is introduced intothe inflation bladder at an elbow having an inlet gland through whichthe liner passes. After the bladder inflates the liner, it enters areceiving canister having a puncturing element positioned in thedownstream manhole. The bladder is sealed against the canister wall andis punctured to allow air to exit through an exhaust. Steam isintroduced at the elbow downstream of the gland pressurized against thebladder. Steam flows through the bladder to cure the resin quickly andcompletely without loss of pressure in the bladder.

Accordingly, it is the object of the invention to provide an improvedmethod for rehabilitation of an existing pipeline by the installation ofa cured in place liner by the pull in and inflate method utilizing airto evert an inflation bladder.

Another object of the invention is to provide an improved method forpull in and inflate installation of a cured in place liner by utilizingflow-through steam to effect cure of the resin.

A further object of the invention is to provide an improved method ofinstallation of a cured in place liner by pull in and inflate whereinair is used to evert the bladder to inflate the liner and flow-throughsteam is used to cure the resin of the bladder which is automaticallypunctured when the bladder enters a receiving canister in the downstreammanhole.

Still another object of the invention is to provide a receiving canisterto puncture automatically the inflation bladder and allow for regulationof air and steam flowing through the inflation bladder.

Still another object of the invention is to provide an improved easementunit for use in the installation of cured in place liner by the pull inand inflate method including a staging reel for holding the length ofinflation bladder to be used.

Yet another object of the invention is to provide an installation elbowincluding a sealing gland to permit introduction of air into theinflation bladder for everting the installation bladder and expandingthe liner and steam for curing.

Still another object of the invention is to provide a manifold toregulate air and steam to be fed to an eversion elbow to effect aireversion of an inflation bladder and flow-through steam for curing.

Still other objects and advantages of the invention will in part beobvious and will in part be apparent from the specification.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to the others, and theapparatuses possessing the features, properties and relation of elementswhich are exemplified in the detailed disclosure and the scope of theinvention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, references had to thefollowing description taken in connection with the accompanying drawingsin which:

FIG. 1 is a perspective view of a length of a typical resin impregnablecured in place liner suitable for use in lining an existing pipeline inaccordance with the invention;

FIG. 2 is a perspective view of the liner of FIG. 1 with the leading endfolded with a cable secured to it for pulling the liner into theexisting pipeline;

FIG. 3 is a cross-sectional elevational schematic view showing pullingin of a resin impregnated cured in place liner of the type illustratedin FIGS. 1 and 2 from a downstream or receiving manhole to an upstreamor eversion manhole at the start of the installation process to line anunderground conduit;

FIG. 4 is a cross-sectional elevational schematic view of the collapsedcured in place liner of FIG. 3 after it is positioned within theexisting conduit at the start of the installation in accordance with theinvention;

FIG. 5 is an elevational view of an eversion apparatus constructed andarranged in accordance with the invention with the eversion bladder andstarter sleeve installed;

FIG. 6 is a cross-sectional elevational view showing the downtube andelbow assembly of FIG. 5 inserted into the liner at the start of theeversion in accordance with the invention;

FIG. 7 is a detailed sketch of the air and steam piping and eversionapparatus in the eversion manhole during an installation;

FIG. 8 is a detailed schematic view of the manifold for controlling airand steam temperature and volume in the process;

FIG. 9 is a cross-sectional elevation view of the reviewing canisterconstructed and arranged in accordance with a preferred embodiment ofthe invention positioned in the receiving manhole before completion ofeversion of the bladder; and

FIG. 10 is a cross-sectional elevational view of a receiving canister inthe receiving manhole as used in accordance with an alternativeembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a flexible cured in place liner 11 of the typegenerally well known in the art. Liner 11 is formed from at least onelayer of a flexible resin impregnable material, such as a felt layer 12having an outer impermeable polymer film layer 13. Felt layer 12 andfilm layer 13 are stitched along a seam line 14 to form a tubular liner.A compatible thermoplastic film in a form of a tape or extruded material16 is placed on or extruded over seam line 14 in order to ensure theimpermeability of liner 11. In the embodiment illustrated in FIG. 1 andused throughout this description, liner 11 includes an inner second feltlayer 17 also stitched along a seam line 18 which is positioned at apoint in the tube other than the location of seam line 14 in outer feltlayer 12. Liner 11 has a leading end 19 with a continuous length storedin a refrigeration unit 21 (FIG. 3) to suppress early cure of the resin.Liner 11 is cut to a desired length after being pulled into the existingpipeline.

Liner 11 of the type illustrated in FIGS. 1 and 2 is impermeable towater and air. This will allow use in an air or water eversion asdescribed above. However, in a pull in and inflate installation inaccordance with the invention, the liner need only be sufficientlyimpermeable to allow for suitable wet out and retention of resin and toprevent damage to the liner as it is pulled into the existing pipeline.

For larger liner diameters, several layers of felt material may be used.Felt layers 12 and 17 may be natural or synthetic flexible resinabsorbable material, such as polyester or acrylic fibers. Impermeablefilm 13 in outer layer 12 may be a polyolefin, such as polyethylene orpolypropylene, a vinyl polymer, such as polyvinyl chloride, or apolyurethane as is well known in the art. In the initial step in alltrenchless rehabilitation installations, the existing pipeline isprepared by cleaning and videotaping.

Prior to commencing installation pursuant to the method in accordancewith the invention, a curable thermosetting resin is impregnated intothe felt of a liner 33 similar to liner 11 by a process referred to as“wet-out”. The wet-out process generally involves injecting resin intofelt layer or layers 12 and 17 of liner 11 through the end or an openingformed in impermeable film layer 13, drawing a vacuum and passing theimpregnated liner through nip rollers as is well known in the liningart. One such procedure of this vacuum impregnation is described inInsituform U.S. Pat. No. 4,366,012, the contents of which areincorporated herein by reference. A wide variety of resins may be used,such as polyester, vinyl esters, epoxy resins and the like, which may bemodified as desired. It is preferable to utilize a resin which isrelatively stable at room temperature, but which cures readily whenheated.

FIG. 2 shows a leading end 32 of a liner 33 with a winch rope or cable22 secured by a slip knot and three half hitches 23 for pulling liner 33into the pipeline. Leading end 32 of liner 33 and cable 22 may be ducttaped to prevent slip of cable 22 and to seal leading end 32.

Referring now to FIG. 3, an existing pipeline 24 located below a surface25 with a section 26 in need of repair between an upstream opening 27and a downstream opening 28. Pipeline section 26 has a plurality ofcracks 29 and a section of missing pipe material 31. There is firstupstream or access at an upstream manhole U and a second downstreamaccess opening at manhole D. Of course, the installation and steps to bedescribed can be done at either end of pipeline section 26 to berepaired. For convenience, the process in accordance with the inventionwill be described with the eversion proceeding from upstream manhole Uto downstream manhole D.

A conventional jetter is used to pull in winch cable 22 into pipelinesection 26 from upstream manhole U to downstream manhole D. Cable 22 isthen connected to leading end 32 of liner 33. Liner 33 is of the typeshown in FIG. 1, but may have a less robust impermeable film than usedin eversion installations. Liner 33 is pulled from refrigeration unit 21positioned at downstream manhole D into pipeline section 26 to berepaired by a winch 34 positioned on an easement unit 36 on surface 25at upstream manhole U.

Winch 34 may be a stand alone unit positioned on surface 25, or bemounted on a vehicle, such as easement unit 36. Easement unit 36includes additional apparatuses such as a bladder staging reel 37including a length of an inflation bladder 38 of a length a safe marginlonger than the length of pipeline section 26 to be repaired. Typically,an excess of about 2 to 15 percent of bladder length is placed onstaging reel 37 is provided, and preferably about 5 to 10 percent inexcess.

Referring now to FIG. 4, installation of resin impregnated liner 33using an improved pull in and inflate method in accordance with theinvention is illustrated. Resin impregnated liner 33 is pulled into thepipeline section 26 to be relined with about a foot of liner 39extending into upstream manhole U. A length of excess of liner 41 ofabout eight to ten feet remains in downstream manhole D. Excess 41 maybe held on surface 25 by a piece of tape or rope 42 secured to a sandbag43. Excess liner 41 is provided to accommodate movement of liner 33 asit is expanded.

In the conventional pull in and inflate installation process utilizing awater eversion process, pressure within the bladder and liner ismaintained due to the height of the water column within the downtube.Cure is initiated by exposing the impregnated liner to heat. This isusually accomplished by introducing heated water into the eversion pipeor by circulating hot water through a recirculation hose pulled into theeverting bladder by a hold back rope connected to the trailing end ofthe everting bladder. Generally, cure takes between about 3 to 5 hoursdepending on the type of resin selected and the thickness of the liner.After cure, entry into the downstream manhole is necessary to releasethe heated water after cure prior to removal of the inflation bladder.

FIG. 5 illustrates an eversion apparatus 44 including a downtube 45 andan eversion elbow 46 used in accordance with a preferred embodiment ofthe invention. Eversion apparatus 44 is mounted on easement unit 36 forconvenience during the installation. An elevating platform 47 oneasement unit 36 allows for easy adjustment of height depending on thedepth of manhole U. Elbow 46 includes an inlet or vertical section 48and an outlet or horizontal section 49. A lower inlet gland or sphinctervalve 51 with an air inlet 52 for pressurizing a flexible element withinlower gland 51 is mounted to the inlet side of vertical section 48. Anupper gland 54 with an air inlet 56 is also mounted to the inlet ofdowntube 45. Both upper gland 54 and lower gland 51 are constructedsimilarly. Each is a spincter valve formed from a flexible elementsecured within an outer cylindrical wall so that a chamber is formedbehind the flexible wall to pressurize the flexible element againstbladder 38. Each gland 51 and 54 is constructed and operates similarlyto the eversion apparatus described in U.S. Pat. No. 5,154,936, thecontents of which are incorporated herein by reference.

Inflation bladder 38 wound on staging reel 37 on easement unit 36 is fedthrough downtube 45, upper gland 54, lower gland 51 and elbow 46.Bladder 38 is then cuffed back and banded to horizontal section 49 ofelbow 46. Upper gland 54 is pressurized against bladder 38 before theeversion begins in order to isolate bladder 38. Air pressure is appliedto air/steam inlet 61 and to bladder 38 sufficient to effect theeversion. Lubricant is applied to the surface of bladder 38 tofacilitate movement through upper gland 54 during the eversion ofbladder 38

Horizontal section 49 of elbow 46 is fitted with a flexible startersleeve 58. Starter sleeve 58 is a length of about two feet of flexiblerobust tubular material banded over bladder 38 with at least one bandingstrap 59. Starter sleeve 58 is sufficiently flexible so that when notsupported it will generally lay flat. When attached to horizontalportion 49 of elbow 46, distal end of starter sleeve 58 lies flat asillustrated in FIG. 6. Eversion apparatus 44 is lowered into upstreammanhole U and the flattened end of starter sleeve 58 is inserted intothe upstream end of liner 33 so that the liner overlaps starter sleeve58 by at least about 3 to 6 inches. Care is taken to maintain startersleeve 58 flat about the end of bladder 38 to avoid introduction of airinto liner 33. Alternatively, liner 33 can be simply secured aboutbladder 38 by banding or the like.

Inflation bladder 38 is formed of a tube of thermoplastic film, such asa polyolefin or polyvinyl chloride. A wide variety of thermoplasticmaterials would be suitable, such as polypropylene or polyurethane solong as the material will withstand the temperatures reached duringcure.

Horizontal section 49 of elbow 46 is formed with an air/stream inletport 61 for receiving air for eversion of bladder 38 and steam for cure.In the illustrated embodiment, elbow 46 also includes a condensate drain62 for removing any condensate that forms in bladder 38 during cure andcool down. After inflation bladder 38 and starter sleeve 58 areinstalled, eversion assembly 44 is positioned in upstream manhole U asshown in FIG. 6.

At this time, inflation of liner 33 is ready to begin. At the start, airat about 5 psi is introduced in to upper gland 54. Once air pressure hasstabilized, inflation bladder 38 is lubricated and permitted to proceedthrough eversion apparatus 44 while maintaining an eversion pressure ofabout 5 psi.

Inflation bladder 38 is everted through starter sleeve 58 by introducingair into air/steam inlet port 61 of elbow 46. In the preferredembodiment, air is introduced from an air inlet line 63 fed through avalve manifold 64 shown in FIG. 8. Air is then directed to air/steaminlet line 65. As inflation bladder 38 passes through starter sleeve 58and enters liner 33, starter sleeve 58 will be locked in against theinlet of pipeline section 26 thereby locking eversion apparatus 44 andelbow 46 in place in upstream manhole U. Inflation bladder 38 continuesto evert through liner 33 until it is brought to a few feet fromdownstream manhole D.

The details of valve manifold 64 and the piping attached to eversionapparatus 44 is shown in FIG. 8. Air enters from air hose 63 through anair pressure regulator 81 and pressure is controlled by an air valve 82.Steam entering from steam hose 77 is regulated by a steam pressureregulator 83 and controlled by a steam valve 84. Air and steam are mixedin air/steam hose 65 after passing through air/steam temperature gauge79 and air/steam pressure gauge 78. Air/steam inlet hose 65 is coupledto manifold 64 and air/steam inlet in elbow 46 by a pair of cam lockfittings 86 or any other convenient hose coupling.

When the eversion continues and bladder 38 approaches downstream manholeD, inflation bladder 38 is stopped at about 5 to 10 feet from downstreammanhole D. The 5 psi air pressure is maintained when the eversion isstopped. At this time, the remaining excess of liner 33 in downstreammanhole D is cut to about one foot from the back face of downstreammanhole D. A sample mold 67 and two screw-type bands 66 are placed overthe end of liner 33. The distal end of liner 33 is then banded about acylindrical receiving canister 68 positioned at the back of downstreammanhole D. Liner 33 is then secured to canister 68 with bands 66.

Canister 68 is a cyclindrical section of rigid material having a closedbackwall 69. A bladder punch 71 is mounted to backwall 69. Bladder punch71 is a sharp tapered tubular member coupled to a condensate drain 72through backwall 69. An exhaust coupling 73 is fitted to condensate adrain 72 and an exhaust hose 74 is coupled thereto. The free end ofexhaust hose 74 is positioned outside of downstream manhole D andsecurely positioned so that any steam-air discharge will not cause asafety hazard. At this time, thermocouples and pressure gauges at thesteam-air discharge to read temperature and stream-air flow may beinstalled.

Receiving canister 68 is positioned securely within downstream manhole Dusing sandbags or other convenient implements. At this time, eversion ofbladder 38 is resumed at the 5 psi air pressure. Inflation bladder 38 iseverted until the nose of bladder 38 reaches backwall 69 of receivingcanister 68. When bladder punch 71 punctures the everting face ofbladder 38 allowing air to exhaust through exhaust hose 74. Pressure ininflation bladder 38 can be controlled by an exhaust value 76 on exhausthose 74.

At this time air pressure between about 20 to 30 psi is applied to lowergland 51 and steam is introduced into air/stream inlet port 61 toinitiate cure of the resin in liner 33. Steam is provided from a steaminlet hose 77 which is regulated by valve manifold 64 to provide anair/steam mixture to air/steam inlet line 65 for providing steam toeversion elbow 46. The air/steam flow is adjusted to maintain a curingpressure of about 7-10 psi until the combined air/steam flowtemperatures reach a desired temperature of about 220° F. measured atexhaust hose 74. Depending upon the particular resin and tube thickness,once the cure is complete, steam flow is turned off while simultaneouslyadjusting the air flow to maintain cure pressured. Exhaust valve 76 isadjusted while cooling to about 150° F.

Once the temperature has cooled to the desired level, air flow pressureis reduced to zero, exhaust valve 76 is fully opened and inflationbladder 38 is slowly de-everted. As bladder 38 de-everts, it will sealoff the punctured end. Accordingly, it is desirable to monitor the airflow pressure to prevent pressure build up. Any condensate that may haveaccumulated in bladder 38 is removed by condensate drain 62 in elbow 46.

In the alternative embodiment illustrated in FIG. 10, a flexiblereceiving sleeve 87 is secured to canister 68 by a pair of bands 66.Receiving sleeve 87 is of the same robust flexible material as startersleeve 58 and operates in the same manner to seal expanding liner 33positioned therein between everting bladder 38 and the insider ofreceiving sleeve 87. As bladder 38 approaches backwall 69 and ispunctured, pressure is maintained within bladder 38 in the same manneras described in connection with FIG. 9.

After bladder 38 has been totally de-everted, it is safe to enterdownstream manhole D and remove sample mold 67 and receiving canister68. Eversion apparatus 44 is then removed from upstream U and any curedliner extending into either manhole is trimmed. At this time, liner 33is now ready for any lateral reinstatement.

It can readily be seen that the process in accordance with the inventionreadily allows one to attain the advantage of curing a resin liner withflow through steam. By practicing the process, a tubular member can beeasily everted through an existing pipeline. By clamping and thencutting an opening in the distal end of the everted tubular member,pressure can be maintained within the everting tubular member and steamcan be introduced at the eversion access and flow through the curingliner to utilize the higher energy available in the steam to cure theresin significantly faster than one can cure utilizing circulating hotwater.

It will thus be seen that the objects set fort above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made and carrying out the above method andin the construction set forth without departing from the spirit andscope of the invention, it is intended that all matter contained in theabove description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed and all statements of the scope of the invention which, as amatter of language, might be said to fall there between.

What is claimed is:
 1. A method for trenchless rehabilitation of anexisting pipeline by pulling a flexible resin impregnated liner into theexisting pipeline from a first access opening to a second access openingand everting a flexible inflation bladder from an eversion access intothe pulled in liner to a receiving access to conform the liner to theexisting pipeline and curing the resin in the liner, comprising:providing a supply of flexible resin impregnated liner and pulling theleading end of the flexible liner into the pipeline from one of theaccess openings to the other access opening with the ends of the linerextending beyond the ends of the pipeline into the access openings;providing a supply of flexible inflation bladder and feeding theinflation bladder into the proximal end of the liner in the eversionaccess; sealingly engaging the inflation bladder in the eversion accessto isolate the interior of the inflation bladder; introducing air intothe bladder in the eversion access downstream of the sealing engagementof the bladder to force the bladder into the interior of the flexibleliner; controlling the speed of eversion of the bladder into the linerby the rate of introduction of air and tension maintained on the bladderuntil the everting bladder extends to the opposite end of the liner;forming an opening in the bladder in the receiving access whilemaintaining pressure in the interior of the bladder and allowing air toflow-through the bladder and exit the receiving access; introducingsteam into the interior of the bladder at the eversion access downstreamfrom the seal on the bladder and allowing the steam to flow through thebladder and exit through the bladder opening; and allowing the resin inthe liner to cure.
 2. The method for trenchless rehabilitation of claim1, including providing the supply of flexible inflation bladder wound ona staging spool positioned at the eversion access.
 3. The method fortrenchless rehabilitation of claim 1, including sealingly engaging theinflation bladder at the eversion access by pressurizing at least oneselectively closeable gland about the bladder.
 4. The method fortrenchless rehabilitation of claim 1, including the step of feeding thebladder into a cylindrical member at the receiving access to restrainexpansion of the bladder.
 5. The method for trenchless rehabilitation ofclaim 4, including puncturing the bladder in the cylindrical member. 6.The method for trenchless rehabilitation of claim 1, wherein forming theopening in the bladder includes the step of everting the bladder into acylindrical receiving canister which forms a seal between the receivingcanister and the bladder and forming an opening in the bladderdownstream of the seal to allow for flow-through through the bladder. 7.The method for trenchless rehabilitation of claim 6, including evertingthe inflation bladder into tubular member and clamping the distal end ofthe inflation bladder everted through the tubular member.
 8. The methodfor trenchless rehabilitation of claim 1, including forming a seal atthe receiving access by banding the distal end of the liner about areceiving canister and everting the bladder in the canister.
 9. Themethod for trenchless rehabilitation of claim 1, including introducingsteam into the bladder by mixing the steam with air prior tointroduction into the interior of the bladder.
 10. The method fortrenchless rehabilitation of claim 1, including applying a greaterpressure to the inflation bladder to sealingly engage the bladder thanthe air pressure introduce to evert the bladder.
 11. The method fortrenchless rehabilitation of claim 1, wherein the step of feeding thebladder includes securing a flexible starter sleeve at the proximal endof the liner and placing the starter sleeve into the liner into theproximal end of the liner and everting the bladder through the startersleeve.
 12. The method for trenchless rehabilitation of claim 1, whereinthe flexible inflation bladder is an impermeable thermoplastic film. 13.The method for trenchless rehabilitation of claim 1, wherein theinflation bladder is a polypropylene film.
 14. The method for trenchlessrehabilitation of claim 1, wherein the inflation bladder is a thinthermoplastic film having a layer of impregnable material on theinterior surface.
 15. An eversion apparatus for use in the installationof a flexible cured in place liner in an existing pipeline, comprising:a tubular member having an inlet opening and an outlet opening; aselectively actuable clamp for receiving an inflation bladder to form aseal about the bladder and to allow the bladder to pass therethrough,the clamp mounted at the inlet opening; and the outlet opening adaptedto secure the bladder thereto and sealingly engage the collapsed liner;a flexible starter sleeve positioned at the outlet opening for evertingthe bladder therethrough to engage the interior of the liner; wherebythe assembled eversion apparatus and bladder can be positioned at oneend of the liner for eversion of the bladder to inflate the liner. 16.The eversion apparatus of claim 15, wherein the clamp is selectivelyactuable by fluid pressure.
 17. The eversion apparatus of claim 15,wherein the claim is a sphincter valve.
 18. The eversion apparatus ofclaim 17, further including a downtube mounted on the inlet side of theclamp.
 19. The eversion apparatus of claim 18, further including anupper clamp valve mounted to the inlet to the downtube.
 20. The eversionapparatus of claim 18, further including an upper sphincter valvemounted to the inlet of the downtube.
 21. The eversion apparatus ofclaim 15, wherein the tubular member includes an elbow with the clampmounted at the inlet to the tubular member.
 22. The eversion apparatusof claim 15, further including a tubular downtube for receiving theinflation bladder mounted to the inlet side of the clamp.
 23. Theeversion apparatus of claim 15, wherein the tubular member is an elbow.24. The eversion apparatus of claim 23, wherein the elbow issubstantially rigid.
 25. The eversion apparatus of claim 24, wherein theelbow includes an air/steam inlet.
 26. A receiving canister for use intrenchless rehabilitation of an existing pipeline, comprising; asubstantially cylindrical member for restraining for restraining aneverting bladder for receiving the everting inflation bladder andforming a seal between the exterior of the bladder and the interior ofthe canister and having a backwall at the distal end of the canister; abladder punch disposed in the backwall of the canister for forming anopening in the everting bladder; and an exhaust connection incommunication with the interior of the receiving canister downstream ofthe face of the everting bladder to provide flow-through from theinterior of the bladder.
 27. The receiving canister of claim 26, whereinthe tubular portion is substantially rigid.
 28. The receiving canisterof claim 26, further including a condensate drain for removal of thecondensate from the canister.
 29. An easement unit for trenchlessrehabilitation of an existing pipeline by inserting a flexible resinimpregnated liner in to an existing pipeline and everting an inflationbladder within the inserted liner to conform the liner to the existingpipeline, comprising: a displaceable vehicle including a frame; a supplyspool of an endless length flexible inflation bladder disposed on theframe; a bladder staging reel disposed on the frame for receiving alength of inflation bladder in a length at least equal to the length ofthe portion of the pipeline to be repaired from the supply spool forfeeding into the liner; and a manifold mounted on the frame andoperatively connected to the interior of the inserted liner forcontrolling the everting and curing fluid to the liner.
 30. A method fortrenchless rehabilitation of an existing pipeline by pulling a flexibleresin impregnated liner into the existing pipeline from a first accessopening to a second access opening and everting a flexible inflationbladder from an eversion access into the pulled in liner to a receivingaccess to conform the liner to the existing pipeline and curing theresin in the liner, comprising: providing a supply of flexible resinimpregnated liner and pulling the leading end of the flexible liner intothe pipeline from one of the access openings to the other access openingwith the ends of the liner extending beyond the ends of the pipelineinto the access openings; providing a supply of flexible inflationbladder and feeding the inflation bladder into the proximal end of theliner in the eversion access; sealingly engaging the inflation bladderin the eversion access to isolate the interior of the inflation bladder;introducing air into the bladder in the eversion access downstream ofthe sealing engagement of the bladder to force the bladder into theinterior of the flexible liner; controlling the speed of eversion of thebladder into the liner by the rate of introduction of air and tensionmaintained on the bladder until the everting bladder extends to theopposite end of the liner; clamping the bladder in the receiving accesswhile maintaining pressure in the interior of the bladder; cutting thedistal end of the everted bladder and allowing air to flow-through thebladder and exit the receiving access; introducing steam into theinterior of the bladder at the eversion access downstream from the sealon the bladder and allowing the steam to flow through the bladder andexit through the bladder opening; and allowing the resin in the liner tocure.
 31. A method for trenchless rehabilitation of an existing pipelineby pulling a flexible resin impregnated liner into the existing pipelinefrom a first access opening to a second access opening and everting aflexible inflation bladder from an eversion access into the pulled inliner to a receiving access to conform the liner to the existingpipeline and curing the resin in the liner, comprising: providing asupply of flexible resin impregnated liner and pulling the leading endof the flexible liner into the pipeline from one of the access openingsto the other access opening with the ends of the liner extending beyondthe ends of the pipeline into the access openings; providing a supply offlexible inflation bladder and feeding the inflation bladder into theproximal end of the liner in the eversion access; sealingly engaging theinflation bladder in the eversion access to isolate the interior of theinflation bladder; introducing air into the bladder in the eversionaccess downstream of the sealing engagement of the bladder to force thebladder into the interior of the flexible liner; everting the bladderthrough the liner until the everting bladder extends to the opposite endof the liner; clamping the distal end of the bladder and forming anopening in the bladder while maintaining pressure in the interior of thebladder and allowing air to flow-through the bladder and exit thereceiving access; introducing steam into the interior of the bladderdownstream from the seal on the bladder and allowing the steam to flowthrough the bladder and exit through the bladder opening; and allowingthe resin in the liner to cure.
 32. The method for trenchlessrehabilitation of claim 31, including everting the bladder through aflexible tubular member at the receiving access; clamping the flexibletubular member and bladder at the receiving access to maintain pressurein the bladder; cutting the distal end of the tubular member andbladder; and attaching the cut tubular member and bladder to a valve topermit flow-through the bladder without loss of pressure therein.
 33. Inmethod for trenchless rehabilitation of an existing pipeline with aresin impregnated liner from a first access opening to a second accessopening by everting a flexible tubular member from one access into theexisting pipeline and curing the resin, the improvement which comprises:providing a supply of flexible tubular member and sealingly engaging thetubular member in the access to isolate the interior of the tubularmember; end of the flexible liner into the pipeline from one of theaccess openings to the other access opening with the ends of the linerextending beyond the ends of the pipeline into the access openings;providing a supply of flexible inflation bladder and feeding theinflation bladder into the proximal end of the liner in the eversionaccess; introducing air into the tubular member downstream of thesealing engagement into the interior of the tubular member; everting thetubular member through existing pipeline; clamping the distal end of thetubular member and forming an opening thereon while maintaining pressurein the interior and allowing air to flow-through the tubular member;introducing steam into the interior of the tubular member downstreamfrom the seal on the tubular member and allowing the steam to flowthere-through and exit through the opening in the tubular member; andallowing the resin to cure.